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Subject: Re: When to do a null move search - an experiment

Author: Vincent Diepeveen

Date: 05:10:03 04/29/04

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On April 28, 2004 at 18:31:48, Sune Fischer wrote:

>>double nullmove:
>>allowed: a3 null null d5 ...
>>allowed: a3 null null d5 null null d4 ....
>>allowed: a3 null d4 null null d5 ...
>I gues the last one should have been
>allowed: a3 null d4 null d5 ...

That will not find zugzwangs.

if there is a zugzwang after a3 null d4, then doing a double null after that
will find it. i am interested in seeing zugzwangs with nullmove. with just 1
rule into my nullmove i can find them without big problems.

>I think the rule is there must be an equal number of nullmoves.
>In special cases the last one might theoreticly fail, ie. if the opponent can't
>undo the zugzwang.
>Say he is forced to capture or move a pawn for instance.
>>That this eats more ply to solve some testset trick like a Bxe4 somewhere, bad
>>luck there.
>Why, because nullmoving misses a deep threat?

Because fullwidth in that Bxe4 position is better because a king must walk from
one side of the board to f2 or something. So the reduction factor is the problem
possibly. Nothing to do with zugzwang.

But the majority of nerds kick on solving testset problems, sehe Isenberg.


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